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Antibiotic dipping studies in relation to uptake, embryonic development and Arizona hinshawii recoveries from turkey hatching eggs.

Antibiotic dipping with gentamicin sulfate by means of the temperature-differential method was effective in reducing but not completely eliminating Arizona hinshawii (7:1, 7, 8) from artificially infected turkey hatching eggs. Embryonic development was well maintained. The antibiotic dip solution intake was variable from egg to egg. Removal of cuticle by means of either 0.2 N HCl or a 10% disodium salt of ethylene diamine tetraacetic acid enhanced egg weight gains and maintained good embryonic development. Complete elimination of A. hinshawii was achieved in one experiment out of four. Correlation studies between egg weight gains and gentamicin concentrations of the contents of the turkey hatching eggs indicated a statistically significant relationship between these two parameters.

Animals↗

Sexual maturation and productivity of Japanese quail fed graded concentrations of mercuric chloride.

Japanese quail (Coturnix c. japonica) were fed 0, 2, 4, 8, 16, and 32 p.p.m. Hg as mercuric chloride (HgCl2) from the time of hatching up to the age of 1 year. None of the birds manifested any gross signs of mercury poisioning. Food consumption, growth rate, and weight maintenance were unaffected. Initial oviposition tended to occur at a younger age as dietary mercuric chloride increased, e.g., the median age at which egg laying began among hens fed 32 p.p.m. Hg was 6 days younger than for controls. The average rate of egg production was positively related to the concentration of mercuric chloride with the most pronounced differences between treatments occurring among young (less than 9-week-old) hens. Beyond 9 weeks of age production was more uniform among the treatments, but even after 1 year hens on 32 p.p.m. Hg were laying an average of 13.5% more eggs than controls. Rate of egg fertilization was generally depressed for all Hg-treatments above 4 p.p.m. Hatchability of fertilized eggs and eggshell thickness appeared unaffected by mercuric chloride.

Animals↗

The effect of luteinizing hormone releasing hormone (L.H.R.H.) on serum L.H. and ovarian growth in turkeys.

Serum L.H. of non-laying hens (NL.) was significantly higher than serum LH of layers (L.). All NL. hens showed a marked increase in serum L.H. within 5 min. of an i.v. injection of 20 or 40 micrograms of L.H.R.H. The L.H. levels of NL. hens were significantly lower at 15 min. after L.H.R.H. injection than at 5 min. The laying turkeys were erratic in their response, with clear cut, small rises in L.H. occurring only in some individuals with hard shelled eggs in utero. Hens with membranous eggs or with empty uteri failed to respond to the L.H.R.H. While F.S.H./L.H. injections caused significant ovarian and oviducal growth, L.H.R.H. given by daily i.m. injection for 7 days or twice daily i.v. injection for 6 days failed to do so. Subcutaneous implants of 1 mg. of L.H.R.H. in polyacrylamide gel led to prolonged elevation in serum L.H.R.H. and increased serum L.H. for about 12 hr. but caused no change in ovarian or oviducal weights.

Animals↗

Serum calcium and phosphorus levels in hens relative to the time of oviposition.

An experiment was conducted to examine the serum calcium and phosphorus level of hens in relation to time of oviposition. Sixty-eight-week-old hens were selected for blood sampling according to the criteria that: 1. they laid an egg the day prior to and the day of blood collection, and 2. the oviposition time on both days was 10 a.m. +/- 2 hours. Samples were taken at hourly intervals, from five hours before through two hours after, and again at four hours after oviposition and were analyzed for serum calcium and phosphorus. All birds received natural and/or artificial light from 4:30 a.m. to 7:30 p.m. each day. Results indicated that serum phosphorus increased from 6.46 to 6.82 mg.% during the period from five to three hours prior to oviposition. Between three and two hours before time of lay, it dropped to a level of 4.75 mg.%, where it remained (+/- 0.35 mg.%) for the remainder of the test period. Serum calcium did not change appreciably during the 10-hour test period. It was hypothesized that the serum phosphorus cycle of the hens is composed of two segments of approximately six and 18 hours duration. The segments were delineated on the basis of activities of bone resoprtion and remineralization and egg shell formation.

Animals↗

Transmission of radioactivity into eggs from laying hens (Gallus domesticus) administered tritium labeled T-2 toxin.

The transmission of radioactivity into eggs from laying hens gastric-intubated with a single or multiple dose of 3-[3H]-T-2 toxin was investigated. In single dosed birds, the maximum radioactivity in eggs occurred at 24 hr after dosing; the yolk and white contained .04 and .13% of the administered radioactivity, respectively. In multiple-dosed birds given 8 consecutive daily doses, the radioactivity in the yolk increased with each dose, whereas the radioactivity in the white increased rapidly until the 3rd dose and thereafter remained constant. In both single- and multiple-dosed birds, the specific radioactivity of the white was greater than that of the yolk. The amount of residue transmitted into an egg in birds intubated daily with 1 mg T-2/kg for 8-consecutive days equivalent to 1.6 ppm dietary T-2) was about .9 microgram (based on specific radioactivity).

Animals↗

The influence of the white-wing feather plumage gene Ww on various quantitative traits in chickens.

The white-wing plumage color gene Ww which acts as an embryonic lethal in homozygotes was studied to determine its pleiotropic effects on various quantitative traits. Two groups of birds Ww/ww+ and ww+/ww+ were compared for mortality, body weight, age to sexual maturity, egg production, egg weight and shape, and egg shell thickness. During 0 to 8 weeks of age, the Ww/ww+ birds showed three times greater mortality than did the ww+/ww+ birds. From 8 to 71 weeks of age their mortality was similar, although during the 36 to 71 week period the Ww/ww+ birds did show a somewhat higher level of mortality. The cause of the mortality was not determined. Body weight was consistently depressed for the Ww/ww+ birds; however, it was not always significantly so. No significant differences were noted among the other traits measured.

Animals↗

The influence of diflubenzuron on several reproductive characteristics in male and female-layer-breed chickens.

The possibility exists for the accidental contamination of feedstuffs used in poultry and livestock feeds with diflubenzuron (Dimilin, TH 6040; N-[[(4-chlorophenyl)amino]-carbonyl]-2, 6-difluorobenzamide), an insect growth regulator. The effect of this insecticide on reproduction in chickens was tested by feeding diflubenzuron at levels of 1, 2.5, 25, and 250 ppm to male and female layer-breed chickens from 1 day of age through a laying cycle. Characteristics measured were egg production, egg weight, eggshell weight, fertility, hatchability, and effects on the progeny. Feeding diflubenzuron at levels up to 250 ppm did not affect the characteristics measured. These results will be useful in evaluating the use of diflubenzuron in the field.

Animals↗

Cyclic changes in plasma phosphorus of laying turkeys.

Plasma phosphorus of laying turkeys measured at 0, 6, 18, and 24 hr after oviposition showed a cyclic pattern similar to that reported for laying chickens. Plasma phosphorus was lowest at oviposition and remained relatively low until 6 hr postoviposition; values at 18 and 24 hr postoviposition were higher. Plasma phosphorus was higher (P less than .05) 24 hr postoviposition than 0 or 6 hr postoviposition. The changes were assumed to be associated with egg shell calcification and bone resorption. Plasma phosphorus values of turkey toms measured during a 24-hr period remained constant and were not significantly (P less than .05) different from each other.

Animals↗

Natural occurrences of ochratoxicosis in poultry.

Five independent episodes of ochratoxicosis in about 970,000 turkeys, two episodes in about 70,000 laying hens, and two episodes in about 12,000,000 broiler chickens were investigated. Ochratoxin A concentrations in suspect feed and ingredients ranged from less than .2 to 16 ppm. Feed samples tested for T-2 toxin, F-2 toxin, heavy metals, and polychlorinated biphenyls were negative. Minor amounts of aflatoxin (less than 60 ppb) were found in suspect feed from two episodes. The main symptoms in turkeys were mortality (up to 59%), nephrotoxicity (pale, swollen kidneys that became tan colored in the sequel to acute toxicity), decreased feed consumption (as little as 20% of the normal feed intake) prior to death, and secondary air sacculitis. Histopathology revealed edema and necrosis of the proximal tubules of the kidneys and no changes in the liver or other organs. Suspect feed containing 2 ppm ochratoxin A increased uric acid levels in serum when fed to poults in the laboratory. The episodes in laying hens were characterized by reduced egg production, poor egg shell quality, and nephropathy. The episodes in broiler chickens were characterized by poor growth rate, poor feed conversion efficiency, poor pigmentation, nephropathy, and increased incidence of air sacculitis. Obtaining feed and ingredients free of ochratoxin, cleaning the feed and ingredient handling equipment, and adding antifungal agents to the feed proved beneficial. Eight of the 9 episodes were traced to the corn supply and the ninth episode was traced to corn gluten meal that became contaminated during storage after manufacture. Evidence was obtained that the ochratoxin was unstable and declined in concentration during storage. Aqueous acetone was a better solvent for extracting ochratoxin than was the recommended phosphoric acid: chloroform. The ochratoxin extracted from high potency samples consisted of ochratoxins A, B, and C in ratios of about 90:8:2.

Animals↗

Dietary interaction of phosphorus with sodium from either chloride or bicarbonate affects laying hen performance.

Experimental diets consisting of two levels of total phosphorus (.30 and .75%) and three different treatments of supplemental sodium (.35% NaCl, 1.40% NaCl, and .35% NaCl plus 1.50% NaHCO3) were fed in a 2 X 3 factorial arrangement to laying hens for 16 weeks. The latter two treatments of sodium were designed to supply the same level of sodium (.55%) from different chemical forms. Hens fed .30% phosphorus laid significantly (P less than .01) less eggs than those fed .75% phosphorus. A highly significant (P less than .01) interaction was found between phosphorus and sodium treatments. The high level of sodium from either chloride or bicarbonate decreased egg production at the lower level of phosphorus and increased it when the higher level of phosphorus was fed. Sodium bicarbonate affected egg production more strongly than sodium chloride did. There were no significant treatment effects on egg weight and egg shell weight. Addition of sodium bicarbonate to the low phosphorus diet significantly (P less than .05) decreased feed consumption of the hen. Supplemental sodium bicarbonate with either level of dietary phosphorus significantly (P less than .05) increased percent nitrogen retention of the hen, but excessive sodium chloride did not.

Animals↗

Dietary self-selection of laying hens inadequate to overcome the effects of high environmental temperature.

Two environmental temperatures, 21 and 30 C, were used during a 28-day experimental period. There were two groups of hens in each temperature treatment. The control groups (C) were given a conventional balanced diet and each dietary self-selection group (S-S) was provided, on an individual hen basis, three diets each one being high in energy, protein, or calcium. The S-S groups had significantly reduced egg production, which probably resulted from the significantly reduced protein intake. Egg weight and energy intake were reduced in the S-S group at 21 C while calcium intake and egg shell strength at 30 C were higher as compared to the corresponding C group. Dietary self-selection did not enable hens to regulate nutrient intake for comparable performance to hens provided one balanced diet. Also, the detrimental effects of high environmental temperature were not overcome by dietary self-selection.

Animals↗

Effects of thermal-induced respiratory alkalosis on blood ionized calcium levels in the domestic hen.

An experiment was conducted to determine the change with time in the blood ionized calcium concentration of hens exposed to an acute heat stress. Five hens were surgically fitted with carotid artery cannulae and placed in cages inside a temperature-controlled chamber. Blood samples were drawn before (23 C), during (35 C), and after (23 C), a 3-hr heat-stress exposure. Whole blood ionized calcium, blood gas, plasma pyruvate, and lactate were determined. Respiratory alkalosis developed 1 hr after the start of heat exposure (35 C). Approximately 1 hr later, there was a concomitant decline in blood pH as plasma lactate and pyruvate concentration increased (P less than .05). In addition, the blood ionized calcium level was reduced (P less than .05) by 19% and was negatively correlated (P less than .05) with plasma pyruvate (-.77) and lactate (-.81). These results suggest that changes in acid-base balance during heat stress reduce the blood ionized calcium level, which may in turn limit the availability of calcium for egg shell formation.

Alkalosis, Respiratory↗

Studies of the pirouette mutation. 2. A detrimental phenotypic interaction with naked neck.

During a study to determine if any genetic linkage existed between the chicken mutations pirouette and naked neck, it was found that when both traits are expressed simultaneously in an individual, an "automutilation" condition can be created in some cases. The tremulous head movements of naked neck-pirouette chicks cause scraping of the skin on the neck against the egg shell during hatching, resulting in lacerations of the neck in varying degrees. Because of this potential for injury, it is suggested that matings between carriers of tremulous neurological disorders and carriers of mutations that result in lack of down cover be avoided whenever possible.

Animals↗